1. Field of the Invention
The present invention relates to a magnetic core for an electromagnetic apparatus to which a coil is to be mounted, and to an electromagnetic apparatus having the magnetic core therefor.
2. Description of the Related Art
As a magnetic core for an electromagnetic apparatus, there has been a type which is formed by an E-shaped core (E type core) and an I-shaped core (I type core), as shown in Japanese patent application laid open No. 2002-134328. As shown in FIG. 16, in the EI type core formed by these two cores, the I-shaped core 102 is fixed to the three leg sections of the E-shaped core 101. Then, a coil (not shown) is mounted around the middle leg section 101 A of the E-shaped core 101, to constitute an electromagnetic apparatus like a transformer or reactor, in which a coil is provided in the opening 103 of the EI type core.
However, as shown in FIG. 6, in the magnetic core for an electromagnetic apparatus of the above described structure, there is a problem that the magnetic resistance against the magnetic flux generated by the coil is high, making it hard for the magnetic flux to flow, because the junctions 104, 105 of the EI-shaped core have rectilinear shapes, with the two parts evenly facing each other, and the end face of the middle leg section 101 A is in contact. Further, as the unit to which the electromagnetic apparatus having said magnetic core is to be mounted becomes lighter and thinner, it is further demanded to lesson the heat generation of the magnetic core, to reduce the leakage of the magnetic flux, and so on. In other words, there is a demand for reducing the magnetic resistance of the magnetic core.
The present invention provides a magnetic core for an electromagnetic apparatus and an electromagnetic apparatus provided with the magnetic core for an electromagnetic apparatus capable of solving the above described problem and reducing magnetic resistance.